Types of coral found in the Arabian Gulf and Sea of Oman can pass defensive adaptations to their offspring that can help protect them from rising sea temperatures, researchers in Abu Dhabi have found.
The findings provide hope for the future of coral reefs facing the ravaging effects of climate change.
The team of researchers at NYU Abu Dhabi and King Abdullah University of Science and Technology, in Saudi Arabia, studied types of reef-building corals that have adapted to the harsher waters of the Arabian Gulf and found that they can pass this resilience on to future generations.
These adaptations are passed down through epigenetics — modifications that affect how often genes are used without actually changing the genetic code. This distinguishes epigenetic modifications from genetic adaptation, which is changes to the genetic code that take place over many generations.
“What we are finding is a surprising amount of potential for both male and female corals to transmit their epigenome [compounds that attach to DNA to change how they’re expressed without changing the DNA itself] to their offspring,” said Youssef Idaghdour, Assistant Professor of Biology at NYUAD, and leader of the local team.
“This research shows the capacity of coral parents to positively impact the resilience of their offspring in environments that are changing too quickly.”
The discovery is welcome news amid an otherwise bleak outlook for coral reefs. One particularly devastating form of coral damage, coral reef bleaching, has wreaked havoc on local coral populations. Almost three-quarters of the country’s coral reefs have been bleached, according to 2018 studies by NYUAD and the Emirates Environmental Agency.
"Climate change represents the most pressing threat to coral reefs globally, with most research estimating widespread loss of corals within the next century,” said Dr John Burt, Associate Professor of Biology at NYUAD.
“Given the long generation times of corals, it has commonly been accepted that the rapid rate of climate change is outpacing the capacity for corals to genetically adapt to cope with increasing temperatures.
“This study demonstrates that epigenetic changes that enhance thermal tolerance can be passed to offspring, dramatically enhancing corals' capacity to rapidly respond to environmental change."
The researchers examined pieces of stony coral taken from the sea off the coast of Abu Dhabi and Fujairah to create epigenetic profiles. The profiles indicated that the hot and saline environment the corals inhabit have strongly affected the epigenetics of the corals as they struggle to thrive in the constantly changing sea temperatures.
The Arabian Gulf is unique in the extremity of the sea temperatures, which can reach higher than 36°C in the summer. The corals there are especially interesting to researchers who use the findings to hypothesise how corals in other parts of the world will cope with rising sea temperatures in the future.